The Long Term Evolution (LTE) is a new terrestrial mobile communication standard currently being standardized by the 3GPP (3rd Generation Partnership Project). The Radio Access Network (RAN) of LTE is named as the Evolved-Universal Mobile Telecommunication Systems Radio Access Network (E-UTRAN). The E-UTRAN physical layer is based on Orthogonal Frequency Division Multiplexing (OFDM). More precisely; the downlink transmission scheme is based on conventional OFDM using a cyclic prefix while the uplink transmission is based on single carrier frequency division multiple access (SC-FDMA) techniques. LTE supports both frequency division duplex (FDD) and time division duplex (TDD).
System Information (SI) in an LTE system is divided into a number of System Information Blocks (SIBs) and Master Information Block (MIB). The MIB includes limited number of most essential and frequently transmitted parameters to acquire other information from the cell. SI is defined in 3GPP TS 36.300 as a Radio Resource Control (RRC) message carrying a number of System Information Blocks (SIBs) that have the same periodicity. Each System Information Block (SIB) contains a set of related system information parameters. System Information BlockType1 (SIB1) is transmitted alone, separately from other SI-messages. SIBs other than SIB1 are carried in SI messages and mapping of System Information Blocks to SI messages is flexibly configurable by using scheduling Information parameters included in SIB1, with restrictions that each SIB is contained only in a single SI message. Only SIBs having the same scheduling (periodicity) requirement can be mapped to the same SI message. In the prior art, the number of SI bits that can be transmitted in any subframe is limited and the SI message should be transmitted in one subframe.
This limits the number of System Information Block (SIB) messages that can be mapped to a single SI message. This decreases the number of SIB messages that can be mapped to a single SI message thereby delaying the acquisition of SI messages by UE, which as a consequence increases the power consumption of UE.
Therefore there is a need to provide flexibility in mapping SIB messages to a single SI message thereby providing opportunity for faster acquisition of SI messages by User Equipment (UE), which as a consequence reduces the UE power consumption.